Renesas 70V27S55PFI

Overview

70V27S55PFI from IDT (now part of Renesas) is a high-speed 32K × 16 dual-port static RAM with true independent left/right port access, 55 ns maximum read/write cycle time, 3.3 V ±0.3 V single-supply operation, and industrial temperature range (–40°C to +85°C). It enables simultaneous memory access in real-time inter-processor communication systems such as radar signal processors and multi-core DSP subsystems.

For engineers reviewing the 70V27S55PFI datasheet, 70V27S55PFI pinout, 70V27S55PFI application, or 70V27S55PFI equivalent, key selection considerations include BUSY/INT flag timing, on-chip semaphore arbitration, LVTTL-compatible I/O, 100-pin TQFP package, and master/slave cascading capability for 32-bit+ data bus expansion.

Technical Context

The 70V27S55PFI implements fully asynchronous dual-port architecture with separate address, control, and bidirectional I/O buses per port. Its on-chip arbitration logic resolves contention via address-match or chip-enable priority, generating push-pull BUSY outputs (not open-drain) and supporting both master (BUSY output) and slave (BUSY input) configurations via M/S pin.

It integrates full hardware semaphore signaling across eight flags addressed by A0–A2, with dedicated SEM enable pins per port and guaranteed tSWRD ≤ 5 ns semaphore write-to-read latency. The device supports byte-selectable writes (UBL/LBL), independent CE0/CE1 per port for power-down control, and automatic low-power standby modes with ISB3 ≤ 0.2 mA (CMOS-level inputs).

Key Specifications

Pinout & Package

70V27S55PFI is housed in a 100-pin TQFP (PN100-1) with 0.5 mm pitch, 14 mm × 14 mm footprint, and exposed thermal pad (not electrically connected). All VDD and VSS pins must be individually decoupled per layout guidelines.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-port SRAM applications.

Compared with CY7C028V-55AXC and AS7C33256B-55TIN, the 70V27S55PFI uniquely delivers integrated semaphore signaling, push-pull BUSY arbitration, and industrial temperature qualification in a single 100-pin TQFP package-reducing BOM count and improving system determinism in safety-critical embedded designs.

Availability

70V27S55PFI is available at Aetrix Electronics and suitable for radar signal processing, digital communication baseband, and multi-core industrial PLC applications requiring stable component supply, long-term lifecycle support, and traceable sourcing.

Supply support for 70V27S55PFI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

IDT (Integrated Device Technology), now part of Renesas Electronics, is a fabless semiconductor company specializing in high-performance timing, memory interface, and RF solutions for communications, computing, and industrial markets.

The IDT70V27 family was designed specifically for deterministic inter-processor communication in real-time embedded systems-emphasizing low-latency arbitration, hardware semaphore support, and industrial-grade reliability without external glue logic.

FAQ

What is the maximum operating frequency supported by the 70V27S55PFI?

The 70V27S55PFI does not specify a clock frequency; it is an asynchronous SRAM. Its performance is defined by access timing: maximum tRC (read cycle time) is 55 ns, enabling effective throughput up to ~18.2 MHz per port under ideal conditions. Actual system bandwidth depends on address/control setup/hold times and bus turnaround overhead-not a fixed clock rate.

Does the 70V27S55PFI support true simultaneous read/write to the same memory location?

Yes, the 70V27S55PFI features true dual-ported memory cells that allow independent, asynchronous read and write operations to the exact same address location from left and right ports simultaneously-without corruption, wait states, or external arbitration logic.

How does the BUSY arbitration work in master vs. slave configuration for the 70V27S55PFI?

In Master mode (M/S = VIH), BUSYL/BUSYR are push-pull outputs asserting when the opposite port initiates conflicting access; in Slave mode (M/S = VIL), they become inputs that inhibit local writes when driven low. This enables hierarchical arbitration in cascaded systems without external logic.

What is the purpose of the SEM pins on the 70V27S55PFI, and how are semaphores accessed?

The SEML and SEMR pins enable hardware semaphore mode. When asserted, A0–A2 select one of eight semaphore flags; I/O0 writes the flag value, and all I/O lines (I/O0–I/O15) read it. tSWRD ≤ 5 ns ensures rapid flag update and visibility across ports.

Can the 70V27S55PFI be used in a 32-bit data bus configuration?

Yes. Using the Master/Slave select (M/S pin) and cascading multiple 70V27S55PFI devices, the data bus can be expanded to 32 bits or wider. One device operates as Master (providing BUSY output), others as Slaves (accepting BUSY input), enabling full-speed error-free operation without discrete logic.